The Siemens SENTRON 3VA1050-4ED42-0KH0 is a 4-pole molded case circuit breaker (MCCB) rated for 50 A continuous current, designed for line protection in distribution panels. Its interrupting capacity hits 121 kA at 240 V — that's the number that governs fault-clearing at the main or subfeed level, not the 50 A frame. At 415 V it still holds 75.6 kA, dropping to 52.5 kA at 440 V and 11.9 kA at 690 V, so it's sized for high-fault industrial services where the available short-circuit current is substantial. The TM210 overcurrent release handles the thermal-magnetic trip curve. Rated continuous current stays flat at 50 A from 40 °C up to 50 °C ambient; above that it derates to 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. That derating curve matters if the breaker sits inside a warm enclosure — the 50 A nameplate is only good if the air around it stays under 50 °C. The front face carries IP40 protection — fine for a dry indoor panel, not for washdown. Auxiliary contact configuration is 2 auxiliary switches plus 1 trip alarm switch (HQ), and the integrated shunt trip release (STL) is ordered separately as 3VA9688-0BL33. No undervoltage release, no ground-fault monitoring, no communication module, no N-conductor protection built in.
Integration & Mounting
Dimensions are 130 mm high, 101.6 mm wide, 70 mm deep. It mounts into a standard distribution panel or enclosure — the 4-pole footprint with the TM210 release and the HQ auxiliary block fits the SENTRON 3VA cutout pattern. The latching endurance is rated at 15 000 cycles, which covers routine switching for a main breaker or infrequent load disconnect. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The trip indicator and voltage trigger (shunt trip) are present, so remote tripping and local fault indication are wired in from the factory — no add-on module needed for those functions.